RESTRICTED T-CELL RECEPTOR EXPRESSION BY HUMAN T-CELL CLONES SPECIFIC FOR MYCOBACTERIAL 65-KDA HEAT-SHOCK PROTEIN - SELECTIVE INVIVO EXPANSION OF T-CELLS BEARING DEFINED RECEPTORS

We have examined the T cell receptor (TcR) expression of clones specific for epitopes of mycobacterial 65-kDa heat-shock protein (hsp65) in the context of two different HLA molecules, and used this system as a model to assess the selection of T cells responsive to this antigen in vivo. DR3-restricted clones were raised from both the synovial fluid (SF) and peripheral blood (PB) of a patient with reactive arthritis in three separate cloning events. Five of five SF-derived clones tested expressed either Vbeta5.2 or a closely related beta chain, Vbeta5.6. The a chains expressed by Vbeta5.2+ and Vbeta5.6+ clones were from different families, Valpha2.4 and Valpha23.2, respectively. Nine of ten clones derived from two cloning procedures on PB taken 3 years later also expressed either Vbeta5.2 or Vbeta5.6. This suggests that the TcR repertoire for recognizing this major histocompatibility complex/peptide complex is relatively restricted and favors the use of Vbeta5. Conservation of the beta chain third complementarity-determining region (CDR3) sequence was not evident, however. Sequencing a and beta chains of representative Vbeta5.2+ and Vbeta5.6+ PB-derived clones revealed TcR which were identical to those utilized by the SF-derived clones, showing that the repertoire for recognition of this antigen is stable over time. Similar studies of TcR expression were carried out on hsp65-specific, DP4-restricted clones derived from the SF of a patient with rheumatoid arthritis by two independent cloning procedures. There was conservation of a chain usage, since all clones expressed a member of the Valpha1 family, but again CDR3 sequence conservation was not apparent. Beta chain usage was not restricted since different clones expressed Vbeta6.7, Vbeta22.3 and Vbeta12. Subtle differences in epitope specificity were detected for two clones with differing TcR. Once more, T cell clones with identical alpha and beta TcR chains were obtained from the separate cloning procedures, suggesting oligoclonalty of T cells with this defined specificity in the patient's SF.